How to get paid for sending emails?

I'm curious, how exactly can someone get paid for sending emails? Is this a legitimate way to earn income, or is it some sort of scam? If it's a viable option, what kind of emails are typically involved, and how does the payment process work? Are there any specific qualifications or skills required to get started with this type of income generation? Lastly, are there any potential risks or drawbacks to consider before diving in?